I have a vehicle with single channel fuel injection.

If you have a single‑cylinder engine or an older vehicle, you may find that both injector terminals show continuity (beep) and the measured resistance is close to 0 ohms on both sides.

This behaviour is normal and typically indicates a single‑channel injection system. In this case you have two options.

Option 1: Use the vehicle wiring diagram

You can look up the wiring diagram for your vehicle and identify the wire insulation colors for battery voltage and the injector signal. Some eFlexFuel kits may include this information.

⚠️Note: Some wiring diagrams reference injector terminal numbers, but we do not recommend relying on these, as they are not always accurate.

Option 2: Use a multimeter to measure DC voltage

If a continuity test does not work or the wire colors are unknown, you can use a multimeter in DC voltage mode to identify the positive terminal.

⚠️This method should be used only when necessary. It may:

• Trigger injector circuit fault codes in the ECU (which must be cleared)
• Produce false readings due to the ECU’s internal diagnostic circuits

Measuring injector voltage safely:

1. Ensure there are no open fuel lines.
2. Turn the ignition ON, but do not start the engine.
3. Connect the multimeter’s black (negative) lead to the vehicle chassis, battery negative terminal, or another solid ground point.
4. Use the red (positive) lead to probe each terminal of the injector connector.
5. The terminal showing battery voltage (+12–13 V) is the positive terminal.

Terminating male-connectors

• Power for eFlexFuel control unit comes from injector channel 1 (yellow wires marked with a red heat‑shrink tube). For this reason, channel 1 must always be connected.
• I you are working with a motorcycle or an engine using staged injection (primary and secondary injectors), connect channel 1 to the primary injectors—these are typically the injectors closest to the cylinder head. Secondary injectors are usually positioned further away, often on top of the intake plenum/air filter housing.
• The eFlexFuel system will operate correctly regardless of injector wiring order. However, if you want the injector numbering in the eFlexFuel app to match the engine’s cylinder order, connect the channels accordingly.
• Before terminating the male connectors:
  • Use a loose male connector to check the correct orientation with the vehicle’s female injector connector.
  • Connect male connector housings to the eFlexFuel wiring harness wires.
  • Ensure that the terminals lock into the connector. Usually, an audible click can be heard when the terminal locks in place. You can also gently tug on the wire to verify that it is properly secured.